Single-roll mill for paint and the like



Sept. 12, 1933. M. LEHMANN El AL 1,926,907

SINGLE ROLL MILL FOR PAINT AND THE LIKE [77. J e/H mn E 6r rid/er Sept. 12, 1933. M. LEHMANN ET AL SINGLE ROLL MILL FOR PAINT AND THE LIKE Filed July 8, 1930 2 Sheets-Sheet 2 Patented Sept. 12, 1933 UNITED STATES PATENT OFFICE Max- and Edgar Griindler, Dresden, Germany, assignors to the firm J. M. Lehmann,

Dresden, Germany Application July 8, 1930. Serial No. 466,566, and

Germany July 13, 1929 6 Claims. (01. 8322) The single-roll mills hitherto known for paint or the like are equipped with a usually reciprocating roll and with an adjustable grinding block cooperating therewith, the admission hopper arranged above the roll, together with the grinding block, being oscillatably pivoted to the mill frame in order to facilitate the cleaning of the mill.

The object of the present invention is to increase considerably the accessibility of the main 10 parts of a single-roll mill with reciprocating grinding block, both in the working position and in the open position, and to enable the grinding block to be cleaned even during the operation of the machine, and to enable it to be changed notwithstanding the presence therein of material to be ground. 1

According to the invention, therefore, the admission hopper is made oscillatable by itself, that is to say, without the grinding block, and similarly the grinding block is oscillatably pivoted to the machine frame by itself, that is to say, separately from the admission hopper. The result is thereby obtained that the admission hopper can be arranged to one side of the roll, and the over-all height of the machine thereby reduced, and above all the charging of the admission hopper is greatly facilitated, and inspection of the interior of the latter is rendered possible, even during th working of the machine, without special appliances.

In addition to the exceptional accessibility in the working position there is also its accessibility in the open position, so that it admits of being particularly easily and quickly cleaned.

Moreover according to the invention the grinding block, with its grinding-block holder, and together with the bearings of the said holder, admits of being rocked out of its working position at any time to be overhauled, and if necessary to be cleaned or exchanged for another grinding block, without the position of the admission hopper, and the material to be ground contained therein, being in the least disturbed.

On each of the two rocking levers of the admission hopper are provided a fine-adjusting lever and two fine-adjusting screws with lock nuts, whereby at any time the admission hopper can be accurately positioned close to the roll, and a constant level of the admission hopper can be 50 adjusted and re-adjusted.

In order to obviate in advance any entrance difficulties of the grinding block, and to assist its reception of material to be ground and consequently the passage of the material between the grinding block and the roll, there is provided in the admission hopper, at the edge of the grinding block facing the on-coming material, a drawingin surface which is tangential to the roll at the grinding block.

The reciprocating of the grinding-block holder, with the grinding block, is effected by a swing lever, the movement of which is obtained by means of an eccentric, a worm wheel and a worm, from the revolution of the roll, in such a way that the said lever engages by means of a slot, open at the top, with the pivot ofvthe oscillatable grindingblock holder, so that during the rocking out of the grinding block the coupling between the grinding-block holder and the swing lever releases automatically, and conversely, during the inward swing, automatically closes.

One constructional form of the invention is illustrated by way of example in the accompanying drawings, in which Figure 1 shows a side elevation of the machine, and

Figure 2 shows in elevation, on a larger scale, one rocking lever and the admission hopper, as Well as a partial section through the roll.

In Figure 3 is illustrated an adjusting device for the grinding block, in section in the axial direction of the grinding-block holder.

Figure 4 is a front view of the machine.

Figures 5, 6 and 7 show on a larger scale the automatic coupling between the grinding-block holder and the swing lever, Figure 5 being a front view corresponding to Figure 4, Figure 6 a side view thereof, and Figure '7 a plan.

The parts indicated in dot and dash lines in the drawings show corresponding parts in a different position.

The material to be ground is placed in an admission hopper 1, which is provided with side walls and an inclined front wall and is closable by a cover 2, and is gradually supplied by the roll 3 to the grinding block 4 spaced from the side walls of the hopper. The admission hopper 1 is pivoted to the mill frame 6 with two rocking 1evers 5, in such a way that it can be rocked out from the roll 3 by means of a worm-wheel segment ,7, a worm 8, and a hand-Wheel 9, and brought right into the tilted position denoted by 1'. A stop 10 provided on the mill frame 6 and variable by means of screw-threads, permits of the coarse adjustment of the admission hopper 1 in relation to the roll 3. Without a special additional device, which serves at the same time as a rectly to the rocking lever 5 but is pivoted by its journal bearing 11 to a fine-adjusting lever 12, which can rotate in a bearing journal 13 on the rocking lever 5. To readjust the admission hop- -per, the rocking lever 5 and the fine-adjusting lever 12 are to a certain extent deflected, into the positions 5' and 12', and then make an obtuse angle'with one another at the bearing journal 13, and the bearing journal 11. of the fine-adjusting lever'12' and "of the admission hopper 1', and therefore also the admission hopper itself, are moved nearer to the roll, withouttheir height 11 being altered, as illustrated in Figure 2. The buckling of the levers 5 and 12 is effected by means of two fine-adjusting screws 14 with butterfly clamping nuts 15, the internal screwthreads of the screws 14 being mounted in a forked extension of the rocking lever 5, this being done by loosening the right hand fine-adjusting screw 14 and tightening the left hand one. A securing pin 16 in one of the two rocking levers 5 engages in an elongated recess in the admission hopper 1 and thereby prevents the admission hopper 1 from falling right over when the rocking levers 5 are being rocked out.

On the mill frame 6, or as Figure 2 shows, on the admission hopper 1, is provided a drawing-in device, adapted to be inserted and re-adjusted in case of need, for the grinding block 4, the operative part of which consists of a plane or even curved, comparatively narrow plate 17, extending over the entire rolling length within the admission hopper, which plate, with its under surface, runs into the contact surface of the grinding block 4 tangentially to the roll 3. In consequence v of the gap between the roll 3 and the drawingin device 17 gradually narrowing in the direction of rotation of the roll, any particles of material present that are too coarse to be seized by the grinding block 4 receive a preparatory rubbing down by the roll 3 and are gradually so far disintegrated that they are taken and ground by the rubbing surface of the grinding block 4 and thus attain the desired degree of fineness. In this way an accumulation of coarse particles of material in front of the grinding block 4 is prevented.

The grinding block 4 is mounted in a special grinding block holder 18, which is equipped with two adjusting devices 19 to 28, which enables the pressure of the grinding block 4 upon the roll 3 to be regulated, and maintain the adjusted pressure without appreciable diminution notwithstanding progressive wear of the grinding block 4. For this purpose there is provided, for each adjusting device 19 to 28, compare Figure 3, a curved member 19, which, with a cover 20, guides a threaded bolt 21, to which is secured an upper spring plate 22. A compression spring 23 is arranged between the upper spring plate 22 and a lower spring plate 24, the shank of which transmits the pressure of the spring 23 through a steel ball 25 to the grinding block 4. A holding pin 26 connects the shank of the lower spring plate 24 in a loose and readily releasable manner with the grinding block 4 and prevents the dropping out of the grinding block 4 when the grinding block holder 18 is deflected. Between the curved member 19 andthe cover 20 there is a fine-adjusting nut 27, by the rotation of which the threaded bolt 21, with the upper spring plate 22, is moved in an axial direction, because the bolt 21 and the spring plate 22 are prevented from rotating in a known manner by means of a feather key and key-way. The fine-adjusting nut 27 is provided with a measuring graduation, which enables the adjustment effected to be read, OII by means of a mark on the curved member or yoke 19. A clamping nut 28 serves as a lock nut for securing the fine-adjusting nut 27 and the threaded bolt 21, with the upper spring plate 22.

The grinding block holder 18 is guided at its end in slide bearings 29, which are rockable on the mill frame 6 in joints 30. Inthe working position each grinding block holder bearing 29 is held fast by a rocking screw 31,.with a wing nut 32. Furthermore for each grinding block holder bearing there is also a device, not shown in the drawings, for taking up the axial thrust arising from the reciprocation of the grinding block 4 and its holder 18. The reciprocation of the grinding block holder 18 is obtained from the roll shaft 33, which carries at one end a worm 34, by which a worm wheel 35 is set in rotation, the shaft 36 of which terminates at each end in an eccentric 37, which engages in a slot guide in a swing lever 38. The upper end of the swing lever 38 is. forked. This fork, when the grinding block holder bearing 29 is rocking in, receives a pivot 39 of the grinding block holder 18, and releases the said pivot during the outward rocking.

On the mill frame 6, underneath each roll bearing, is provided a positioning screw 40, with a lock nut, in order that the roll 3 may also be adjustable relatively to the grinding block 4, because it is particularly important for the satisfactory working of the machine that the distance of the roll axis 33 from the axis of the grinding block holder 18 should be uniform.

By a scraping device 41 of known construction the ground material is removed from the roll 3 and supplied through an outlet 42 to its destination. In order to guard against unnecessary evaporatlon of solvents and the like during the working of the machine the roll 3 is enclosed in its upper portion between the admission hopper 1 and the outlet 42. Nevertheless a window 43 enables the correct adjustment of the scraping device 41 and the uniform discharge of the ground material to be observed. For the driving of the machine, fast and loose pulleys 44 and 45 are provided.

The cooling of the roll 3 is usually necessary, so the roll is made hollow, as shown in Figures 2 and 4. The cooling water enters through a pipe connection 46, passes through a cooling pipe 47 into the roll 3, flows back after the cooling through the hollow shaft 33, and flows by way of a discharge ring 48 into a catch box 49, from which it is removed by a discharge pipe 40. In case of need provision may be made for cooling or varying the temperature of the admission hopper 1, which woiilld then likewise he usually made with double wa s.

Without affecting the essence of the invention two or more grinding blocks 4 may be provided instead of one, and these would come into action on the roll 3 one after the other.

It may further be emphasized that the drawing-in device 1'7 for the grinding block 4 is mainly advantageous for the treatment of a material which although substantially free from foreign admixtures is still rather lumpy or mixed with more or less numerous coarse particles of material. Without this drawing-in device 1'7, however, the known cleaning action of the grinding block 4 comes primarily into action and is capable of holding back all coarser particles of any kind. This cleaning and filtering action of the grinding block 4 is of course particularly desirable and advantageous when the material in itself is already rather fine-grained and thinly liquid, or contains practically no coarse-grained particles, but contains undesirable foreign bodies such as threads, films and the like. The construction of the machine then has the advantage that all the impurities that accumulate before the grinding block 4 are outside the material awaiting treatment in the admission hopper, and present themselves to the eye, and can therefore easily be drawn on one side and removed from the grinding block 4 and the roll 3.

What we claim is:-

1. A mill for grinding paint and the like, com prising a single grinding roll, an outwardly swingable admission hopper having side walls normally located laterally of the grinding roll and adapted to hold material to be ground in contact with part of the periphery of the grinding roll, and a grinding block spaced. from the side walls of the hopper and located at the upper part of the periphery of the grinding roll beyond that part of the grind-- ing roll that is in contact with the material in the admission hopper.

2. A mill for grinding paint and the like, comprising a single grinding roll, an admission hopper having side walls and located at one side of the grinding roll and adapted to hold material to be ground in contact with part of the periphery of the grinding roll, means for rockably mounting the hopper laterally of the roll so that the hopper may be swung outwardly therefrom and a grinding block spaced from the side walls of the hopper and located at the top of the roll, beyond that part of the periphery of the grinding roll that is in contact with the material in the admission hopper.

3. A mill for grinding paint and the like, comprising a machine frame, a single grinding roll joumaled in the machine frame, a rocking frame rockably mounted on the machine frame, an admission hopper, trunnions on the admission hopper, the hopper being tiltably supported by the said trunnions on the rocking frame and being adapted to hold material to be ground normally in contact with part of the periphery of the grinding roll and to be rocked away from the grinding roll when desired, and a grinding block located at a part of the periphery of the grinding roll beyond the part that is in contact with the material in the admission hopper.

4. A mill for grinding paint and the like, comprising a machine frame, a single grinding roll joumaled in the machine frame, a rocking frame rockably mounted on the machine frame, an admission hopper adapted to hold material to be ground in contact with part of the periphery of the grinding roll, trunnions on the admission hopper, the hopper being tiltably supported by the said trunnions on the rocking frame and bein adapted to hold material to be ground normally in contact with part of the periphery of the grinding roll, and to be rocked away from the grinding roll when desired, means for the fine adjustment of the position of the admission hopper in relation to the grinding roll, and a grinding block located at a part of the periphery of the grinding roll beyond the part that is in contact with the material in the admission hopper.

5. A mill for grinding paint and the like comprising a machine frame, a single grinding roll journaled in the machine frame, a rocking frame rockably mounted on the machine frame, an admission hopper adapted to hold material to be ground in contact with part of the periphery of the grinding roll, trunnions on the admission hopper, the hopper being tiltably supported by the said trunnions on the rocking frame and being adapted to hold material to be ground normally in contact with part of the periphery of the grinding roll, and to be rocked away from the grinding roll when desired, two levers for the fine adjustment of the position of the admission hopper in relation to the grinding roll, a fineadjusting screw on each of the said levers, a fine-adjusting nut co-operating with each of the said screws, and a grinding block located at a part of the periphery of the grinding roll beyond the part that is in contact with the material in the admission hopper.

6.'A mill for grinding paint and the like, comprising a machine frame, a single grinding roll journaled in the machine frame, a rocking frame rockably mounted on the machine frame, an admission hopper carried by the rocking frame and adapted to hold material to be ground normally in contact with part of the periphery of the grinding roll and to be rocked away from the grinding roll when desired, a second rocking frame rockably mounted on the machine frame, and a grinding block mounted on the second rocking frame, normally located at a part of the periphery of the grinding roll beyond the part that is in contact with the material in the admission hopper but capable of being rocked away from the grinding roll.

MAX LEHMANN. EDGAR GRUNDLER. 

